Frictionally driven belted work vehicle

Abstract

An elastomeric belt laying vehicle is disclosed for transmitting greater tractive effort to the earth as compared to comparably powered wheel vehicles and being operable at high speed on improved road surfaces without inflicting damage thereto. A pair of the wheels are arranged on each lateral side of the vehicle's chassis for support thereof. An inextensible, endless belt is highly tensioned throughout its length, is entrained about each pair of wheels, and is frictionally, drivingly coupled to at least one wheel of each pair. The structure of the belt, structure of the wheels and cooperating components thereof ensure engagement therebetween, provides long service with minimum maintenance thereof, and supplies the necessary frictional couple to effectively transmit driving torque from the wheels to the belt.

We claim:  
     
       1. A belt laying work vehicle comprising: 
       a frame having opposed lateral sides;  
       a pair of longitudinally separated wheel structures having radially outwardly facing outer peripheral surfaces and being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver;  
       a pair of endless, inextensible belts each having opposite lateral sides and an interior surface and each being entrained about a respective pair of said wheel structures, a plurality of laterally extending grooves being disposed on one of said interior surface and said outer peripheral surface of each belt and entrained driver, respectively, for removing debris from therebetween;  
       means for controllably tensioning and urging each belt's interior surface and said outer peripheral surface of the associated driver into frictional driven engagement;  
       means for distributing a predetermined portion of the weight of said frame to the interior surface of each belt longitudinally between said wheel structures of each pair;  
       means for rotating each of said drivers;  
       guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface; and  
       said driver wheel structure having a circumference which is maintained substantially constant during rotation and under driving load.  
     
     
       2. A belt laying vehicle, as set forth in claim  1 , wherein said weight distribution means includes; 
       a mounting structure connected to said frame;  
       a first and second support arm pivotally connected to said mounting structure about a pivot axis;  
       a first and a second roller structure being respectively rotatably joined to said first and second support arms; and  
       means for biasingly transmitting forces exerted on one of said support arms by the roller structure joined thereto to the other roller structure through said other support arm.  
     
     
       3. A belt laying vehicle, as set forth in claim  2 , wherein said guiding means includes a plurality of longitudinally separated alignment members, and each of said roller structures includes a pair of laterally separated rollers which define a guiding slot adapted for receiving said alignment members. 
     
     
       4. A belt laying vehicle, as set forth in claim  3 , wherein each of said alignment members has a locating surface and is connected to and extends interiorly from a respective belt, and a positioning surface connected to each wheel structure and positioned laterally adjacent said locating surfaces. 
     
     
       5. A belt laying vehicle, as set forth in claim  2 , wherein said means for biasingly transmitting forces includes a force transfer member pivotally connected to said mounting structure and a resilient structure arranged between said force transfer member and each support arm. 
     
     
       6. A belt laying work vehicle comprising: 
       a frame having opposed lateral sides;  
       a pair of longitudinally separated wheel structures being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver having a laterally rigid drum and a radially thin layer of elastomer joined directly to said drum, each elastomer layer having a radially outwardly facing outer peripheral surface;  
       a pair of endless, inextensible belts each having opposite lateral sides and an interior surface and each being entrained about a respective pair of said wheel structures;  
       means for controllably tensioning and urging each belt's interior surface and said outer peripheral surface of the associated driver into frictional driven engagement;  
       means for rotating each of said drivers;  
       guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface; and  
       said driver wheel structure having a circumference which is maintained substantially constant during rotation and under driving load.  
     
     
       7. The belt laying vehicle of claim  6 , including means for distributing a predetermined fraction of the weight of said frame to the interior surface of each belt longitudinally between said wheel structures of each pair. 
     
     
       8. The belt laying vehicle of claim  7 , wherein said weight distribution means includes: 
       a mounting structure connected to said frame;  
       a first and second arm pivotally connected to said mounting structure about a pivot axis;  
       a first and a second roller structure being respectively rotatably joined to said first and second arms; and  
       means for biasingly transmitting forces exerted on one of said arms by the roller structure joined thereto to the other roller structure through said other arm.  
     
     
       9. The belt laying vehicle of claim  8 , wherein each of said roller structures includes a pair of laterally separated rollers which define a guiding slot adapted for guidingly receiving said guide means' enterengaging belt portion. 
     
     
       10. A belt laying work vehicle comprising: 
       a frame having opposed lateral sides;  
       a pair of longitudinally separated wheel structures having radially outwardly facing outer peripheral surfaces and being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver;  
       a pair of endless, inextensible belts each being entrained about a respective pair of said wheel structures and including a body portion bounded by opposed interior and exterior surfaces and opposed lateral sides, said body portion having reinforcing structure disposed therein between said lateral sides, a plurality of laterally extending grooves being disposed on one of said interior surface and said outer peripheral surface of each belt and entrained driver, respectively;  
       means for controllably tensioning and providing a majority of a frictional driven engagement by urging each belt's interior surface and said outer peripheral surface of the associated driver into said frictional driven engagement;  
       means for rotating each of said drivers;  
       a plurality of longitudinally separated elastomeric alignment members joined to the interior surfaces laterally between the lateral extremes of said reinforcing structure, said alignment members being laterally engageable with said wheel structures; and  
       said drive wheel structure having a circumference which is maintained substantially constant during rotating and under driving load.  
     
     
       11. A belt laying work vehicle comprising: 
       
         a frame having opposed lateral sides;  
       
       
         a pair of longitudinally separated wheel structures having radially outwardly facing outer peripheral surfaces and being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver;  
       
       
         a pair of endless, inextensible belts each being entrained about a respective pair of said wheel structures and including a body portion bounded by opposed interior and exterior surfaces and opposed lateral sides, said body portion having reinforcing structure disposed therein between said lateral sides;  
       
       
         means for controllably tensioning and providing a majority of a frictional driven engagement by urging each belt's interior surface and said outer peripheral surface of the associated driver into said frictional driven engagement;  
       
       
         means for distributing a predetermined portion of the weight of said frame to the interior surface of each belt longitudinally between said wheel structures of each pair;  
       
       
         means for rotating each of said drivers; and  
       
       
         guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface, and said driver wheel structure being rigid and having a circumference which is maintained substantially constant during rotation under driving load. 
       
     
     
       12. The belt laying work vehicle of claim  11  wherein said wheel structure includes a laterally rigid drum. 
     
     
       13. The belt laying work vehicle of claim  11  wherein said means for distributing a predetermined portion of a weight of said frame includes: 
       
         a mounting structure connected to said frame;  
       
       
         a first and second support arm pivotally connected to said mounting structure about a pivot axis;  
       
       
         a first and second roller structure being respectively rotatable joined to said first and second support arms; and  
       
       
         means for biasingly transmitting forces exerted on one of said support arms by the roller structure joined thereto to the other roller structure though said other support arm. 
       
     
     
       14. A belt laying work vehicle comprising: 
       
         a frame having opposed lateral sides;  
       
       
         a pair of longitudinally separated wheel structures being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver having a laterally rigid drum and said drum defining a radially outwardly facing outer peripheral surface;  
       
       
         a pair of endless, inextensible belts each having opposite lateral sides and an interior surface and each being entrained about a respective pair of said wheel structures;  
       
       
         means for controllably tensioning and providing a majority of a frictional driven engagement by urging each belt's interior surface and said outer peripheral surface of the associated driver into said frictional driven engagement;  
       
       
         means for distributing a predetermined portion of the weight of said frame to the interior surface of each belt longitudinally between said wheel structure of each pair;  
       
       
         means for rotating each of said drivers;  
       
       
         guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface; and  
       
       
         said drive wheel structure being rigid and having a circumference which is maintained substantially constant during rotation and under driving load. 
       
     
     
       15. A belt laying work vehicle comprising: 
       
         a frame having opposed lateral sides;  
       
       
         a pair of longitudinally separated wheel structures having radially outwardly facing outer peripheral surfaces and being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a driver;  
       
       
         a pair of endless, inextensible belts each being entrained about a respective pair of said wheel structures and including a body portion bounded by opposed interior and exterior surfaces and opposed lateral sides, said body portion having reinforcing structure disposed therein between said lateral sides;  
       
       
         means for controllably tensioning and providing a majority of a frictional driven engagement by urging each belt's interior surface and said outer peripheral surface of the associated driver into said frictional driven engagement;  
       
       
         means for distributing a predetermined portion of the weight of said frame to the interior surface of each belt longitudinally between said wheel structures of each pair;  
       
       
         means for rotating each of said drivers;  
       
       
         guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface; and  
       
       
         said drive wheel structure being rigid and having a circumference which is maintained substantially constant during rotation under driving load. 
       
     
     
       16. A belt laying work vehicle comprising: 
       
         a frame having opposed lateral sides;  
       
       
         a pair of longitudinally separated wheel structures having radially outwardly facing outer peripheral surfaces and being mounted in supporting relation to said frame on each lateral side thereof and at least one of each pair including a rigid driver;  
       
       
         a pair of endless, inextensible, reinforced belts each having opposite lateral sides and an interior surface and each being entrained about a respective one of said pair of wheel structures;  
       
       
         a controllable tensioning apparatus including a cylinder arrangement operative to apply a force separating the longitudinally distal portions of each of said pair of longitudinally separated wheel structures providing a majority of a frictional driven engagement by urging each belt's interior surface and the outer peripheral surface of the pair of longitudinally separated wheel structures into said frictional driven engagement;  
       
       
         means for distributing a predetermined portion of the weight of said frame to the interior surface of each belt longitudinally between said wheel structures of each pair;  
       
       
         means for rotating each of said drivers;  
       
       
         guiding means including interengaging portions of said wheel structures and entraining belt for minimizing lateral movement of each belt relative to the respective entrained wheel structures and for radially localizing lateral engagement of each belt and the respective entrained driver to locations substantially adjacent said outer peripheral surface; and  
       
       
         said driver wheel structure being rigid and having a circumference which is maintained substantially constant during rotation under driving load. 
       
     
     
       17. The belt work vehicle of claim  16  further including a plurality of laterally extending grooves being disposed on one of said interior surface and said radially outwardly facing outer peripheral surface of each belt and each of said rigid drive wheel respectively. 
     
     
       18. An agricultural tractor, comprising: 
       
         a frame and an engine supported on the frame;  
       
       
         two pairs of longitudinally spaced wheels, apparatus mounting one pair of wheels on one side of the frame and the other pair on the other side, at least one of each pair including a rigid driver driven by the engine, each wheel having a generally circumferential outer peripheral surface, and each driver being so constructed and arranged that its circumference is maintained substantially constant during rotation under driving loads;  
       
       
         first and second endless, substantially inextensible, reinforced belts each having an interior surface and each being entrained about a respective pair of the wheels;  
       
       
         a plurality of longitudinally spaced rollers located between the wheels of each pair and engaged with the interior surface of the respective belt for distributing a portion of the weight of the tractor to the belt;  
       
       
         a guiding arrangement including interengaging portions of the wheels and entrained belt to minimize lateral movement of each belt relative to the wheels it is entrained about and to radially localize lateral engagement of each belt and its respective driver to locations adjacent the driver's outer peripheral surface; and  
       
       
         a tensioning apparatus including a pair of hydraulic cylinders each having a head end and a rod end and each operatively associated with a respective pair of wheels and their entrained belt to urge the wheels longitudinally further apart, thereby tensioning each belt's interior surface providing a majority of a frictional driven engagement with the outer peripheral surface of its respective driver. 
       
     
     
       19. The agricultural tractor of claim  18  further including a plurality of laterally extending grooves being disposed on one of said interior surface and said generally circumferential outer peripheral surface of each belt and each of said rigid drive wheel respectively. 
     
     
       20. A belt laying heavy- duty work vehicle, comprising:    
       
         a frame having opposed lateral sides;  
       
       
         a set of longitudinally separated wheel structures being mounted in supporting relation to said frame on each lateral side thereof, each of said set of wheel structures including a pair of wheels, said wheels having radially outwardly facing outer peripheral surfaces, at least one of said pair of wheels being a driver;  
       
       
         a pair of endless, inextensible, reinforced belts each being entrained about a respective one of said pair of wheel structures and including a body portion bounded by opposed interior and exterior surfaces and opposed lateral sides;  
       
       
         a tensioning apparatus including at least one hydraulic cylinder operatively associated with each set of wheel structures to regulate tension of each of the belts by urging the longitudinal separation of said pair of wheels of each of said longitudinally separated wheel structures maintaining each pair of belt's interior surface in driving relationship by providing a majority of a frictional driven engagement with the respective outer peripheral surface of the set of wheel structures;  
       
       
         a set of rollers carried between each of said longitudinally separated wheel structures and disposed to engage the interior surface of each belt and to distribute a portion of the weight of said frame longitudinally between said pair of wheels of each of said wheel structures;  
       
       
         means for rotating each of said drivers;  
       
       
         a guide apparatus including a portion of said wheel structures that engages a portion of said entraining belt to minimize lateral movement of each belt relative to the respective entrained wheel structures, each wheel structure portion and respective belt portion being located to radially localize lateral engagement of the respective belt and entrained driver to locations substantially adjacent said outer peripheral surfaces of said wheel structures; and  
       
       
         each drive being rigid and having a circumference which is maintained substantially constant during rotation under driving loads. 
       
     
     
       21. The belt laying work vehicle of claim  20  wherein said tensioning apparatus applies a tension force necessary to frictionally couple said endless, inextensible belts and said respective drivers. 
     
     
       22. The belt laying work vehicle of claim  21  wherein said tension force, when multiplied by the coefficient of friction between the drive wheel structure and the belts, is at least as great as the predetermined driving force which the engine can exert on the ground through the belts. 
     
     
       23. The belt laying work vehicle of claim  21  wherein said pair of endless, inextensible belts have a width and said tension force is about  17 , 00  Newtons per lateral centimeter of belt width. 
     
     
       24. The belt laying work vehicle of claim  20  wherein said tensioning apparatus is arranged to move each of said other wheels longitudinally away from its respective driver. 
     
     
       25. The belt laying work vehicle of claim  20  wherein said tensioning apparatus includes a recoil apparatus. 
     
     
       26. The belt laying heavy- duty work vehicle of claim  20  further including a plurality of laterally extending grooves being disposed on one of said interior surface and said radially outwardly facing outer peripheral surface of each belt and each of said driver respectively.